nestopia/source/core/board/NstBoardWaixingFs304.cpp
2021-08-25 22:20:30 -04:00

106 lines
2.9 KiB
C++

////////////////////////////////////////////////////////////////////////////////////////
//
// Nestopia - NES/Famicom emulator written in C++
//
// Copyright (C) 2021 Rupert Carmichael
//
// This file is part of Nestopia.
//
// Nestopia is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// Nestopia is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Nestopia; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
////////////////////////////////////////////////////////////////////////////////////////
#include "NstBoard.hpp"
#include "NstBoardWaixing.hpp"
// Reference: https://github.com/TASVideos/fceux/blob/master/src/boards/164.cpp
namespace Nes
{
namespace Core
{
namespace Boards
{
namespace Waixing
{
void Fs304::SubReset(bool)
{
Map( 0x5000U, 0x5FFFU, &Fs304::Poke_5000 );
regs[0] = 0x3;
regs[1] = 0x0;
regs[2] = 0x0;
regs[3] = 0x7;
UpdatePrg();
}
void Fs304::SubSave(State::Saver& state) const
{
const byte data[4] = { regs[0], regs[1], regs[2], regs[3] };
state.Begin( AsciiId<'3','0','4'>::V ).Begin( AsciiId<'R','E','G'>::V ).Write( data ).End().End();
}
void Fs304::SubLoad(State::Loader& state,const dword baseChunk)
{
NST_VERIFY( baseChunk == (AsciiId<'3','0','4'>::V) );
if (baseChunk == AsciiId<'3','0','4'>::V)
{
while (const dword chunk = state.Begin())
{
if (chunk == AsciiId<'R','E','G'>::V)
{
State::Loader::Data<4> data( state );
regs[0] = data[0];
regs[1] = data[1];
regs[2] = data[2];
regs[3] = data[3];
}
state.End();
}
}
}
void Fs304::UpdatePrg()
{
switch (regs[3] & 0x5) {
case 0:
prg.SwapBank<SIZE_32K>( 0x0000, ((regs[0] & 0xC) | (regs[1] & 0x2) | ((regs[2] & 0xF) << 4)) );
break;
case 1:
prg.SwapBank<SIZE_32K>( 0x0000, ((regs[0] & 0xC) | (regs[2] & 0xF) << 4) );
break;
case 4:
prg.SwapBank<SIZE_32K>( 0x0000, ((regs[0] & 0xE) | ((regs[1] >> 1) & 0x1) | ((regs[2] & 0xF) << 4)) );
break;
case 5:
prg.SwapBank<SIZE_32K>( 0x0000, ((regs[0] & 0xF) | ((regs[2] & 0xF) << 4)) );
break;
}
}
NES_POKE_AD(Fs304,5000)
{
regs[(address >> 8) & 0x3] = data;
UpdatePrg();
}
}
}
}
}